Metallic materials and human civilization
From the mysterious shape-memory alloys to the future star of energy materials--hydrogen storage alloys
Ancient ceramics--The old look has changed into the new look
From an ancient material kingdom to the renewed splendor of the modern inorganic materials.
Incredibly powerful advanced structural ceramics to marvelous functional ceramics.
Young polymers--a variety of forms
The emerging materials kingdom in the 20th century--polymer materials for modern life
Functional polymers show their abilities
Advanced composites--a masterpiece of craftsmanship
New functional materials--a stepping stone for the progress of human civilization
Biomaterials, information materials, environmental materials, nanomaterials, and nanomaterials, which can be used in the development of the human civilization. Biomaterials, information materials, environmental materials, nanomaterials, energy materials and smart materials
Materials - the cornerstone of human civilization
Several active fields of materials science and technology
1. Biomaterials: including biomedical materials and biomimetic materials.
2. Smart materials: such as piezoelectric ceramics and shape memory alloys.
3. Environmental materials; 4 . Nanomaterials
5. Functional polymers: water-absorbent polymers, conductive polymers, light-emitting organic polymers, polymer shape memory, polymer electrolytes, polymer piezoelectricity, organic nonlinear optical materials, degradable polymers and polymer liquid crystals, etc.
6.
6. Computer simulation and material design: computer simulation to predict the structure of materials, properties and their relationships, so as to achieve material design, forming a "computational materials science".
Polymer science is not only an applied discipline, but also a basic discipline, it is built on the basis of organic chemistry, physical chemistry, biochemistry, physics and mechanics and other disciplines gradually developed into a new discipline.
Highly Fractional Science
Highly Fractional Chemistry
The study of the principles of polymerization and polymer chemistry, selection of raw materials, to determine the route, to find catalysts, and the development of synthetic processes.
The study of the relationship between the structure and properties of polymers, for the design and synthesis of polymers with predetermined properties to provide theoretical guidance, is the bridge between synthesis and application.
Polymer Physics
Polymer Processing
The study of the principles and techniques of polymer processing and molding.
Polymer Science
l 1839 American Goodyear invented the vulcanization of natural rubber.
l 1855 British Parks made cellulose plastic (nitrocellulose + camphor).
l 1883 Frenchman de Chardonnet invents rayon.
l The concept of macromolecules (polymers) and the emergence of polymer science began in the 1920s.
l In 1920, Staudinger published his groundbreaking document "On Polymerization", in which he introduced the concept of long-chain polymer structures. In 1938 tetrafluoroethylene was polymerized...
Polyethylene was synthesized by Ziegler in 1953 at low pressure, followed by polypropylene synthesized by Natta, and Ziegler and Natta were awarded the Nobel Prize for Chemistry in 1963.
The miracle of polymerization
The discovery of plastics
The invention of celluloid in 1869 by John Hiatt, a 31-year-old printer
The invention of phenolic resins by Bakelite in 1909
Polymers in modern life-plastics
Engineering plastics in modern life
The development of rubber
Rubber The development of
Tears of oak
Ugly but favored synthetic rubber
Modern life in the polymer materials-rubber
1855 Swiss Ottimus cellulose in nitric acid to get nitrocellulose solution, the first rayon;
1884 Chattanooga put nitrocellulose in alcohol and ether to get a solution, to get rayon;
1884 Chattanooga in alcohol and ether to get a solution, to get rayon
Development of fibers
Development of functional polymer materials
Functional polymer materials began to develop in the late 1960s.
Functional polymers are polymers and their composites that have chemical reaction activity, catalytic properties, photosensitivity, electrical conductivity, magnetism, biocompatibility, pharmacology, selective separation, or have the function of converting or storing substances, energy and information.
The functional polymers that have reached practical use are: ion exchange resins, separation of functional membranes, photoresists, photographic resins, polymer slow-release drugs, artificial organs and so on.
Polymer sensitive components, highly conductive polymers, high resolution separation membrane, high sensitivity polymers, polymer solar cells and other functional polymer materials, will soon reach the stage of practical use.
Functional Polymer Materials-Highly Absorbent Resin
Highly Absorbent Resin is a kind of functional polymer materials, which has excellent water absorption and water retention function, and can absorb hundreds or thousands of times of its own weight, and has been crowned as "super adsorbent".
The main types are polyacrylates, polyvinyl alcohols, vinyl acetate*** polymers, polyurethanes, starch-adjacent*** polymers, etc. The main types of polyacrylates are acrylates, polyvinyl alcohols, vinyl acetate*** polymers, polyurethane, and starch-adjacent*** polymers. Polyacrylates are produced by reverse polymerization with acrylic acid and caustic soda as the main raw materials.
Can be made into women's sanitary napkins, baby diapers and paper napkins, etc., but also can be used as indoor air fragrances, vegetables, fruits, preservatives, mildew agents, flame retardants, moisture-proof agent and water-absorbing children's toys after the volume expansion.
At present, the total production capacity of the world has exceeded 1.3 million tons/year, of which Japan Catalyst Chemical Company is the world's largest production company, with a production capacity of 250,000 tons/year.
Polymer membrane refers to those by the special separation function of polymer materials made of thin films, can selectively separate substances. Currently used in seawater desalination, reverse osmosis, membrane extraction, membrane distillation and other technical fields.
Polymer separation membrane
Built in Saudi Arabia's Kita water plant, is the world's largest desalination plant, the daily supply of 12,000 tons of fresh water, the main use of cellulose acetate separation membrane device.
Photosensitive polymer materials, represented by photosensitive resins, are mainly used in photography, printing plates, printed integrated circuits.
The printing industry uses polyvinyl alcoholate, crosslinking and insoluble in the light and retained to get letterpress.
Photolithography is a photoresist in which diazoquinone is attached to phenolic resin, and the light decomposes the diazoquinone, and the image is retained with a resolution of 10 nanometers.
Photosensitive polymer materials
In 1950, people gradually began to wear contact lenses made of polymethyl methacrylate (PMMA), which has superior optical properties and can correct corneal astigmatism. In 1960, Czech scholars invented soft contact lenses using a decade of material, that is, hydroxy ethyl methacrylate (HEMA), which has been used to this day.
Functions
Functional polymer materials - contact lenses
In the plastic by adding light-emitting materials can be made into light-emitting plastics. Luminescent plastic is a new type of high value-added functional materials in recent years. Its products such as: transportation field channel marking, stairway marking, marking line; light-emitting paint, light-emitting light, light-emitting wallpaper, handicrafts, toys, sports and leisure goods.
Functional polymer materials - light-emitting materials
Conductive polymers since the date of discovery has become a hot spot in materials science research. At present, it has become a new multidisciplinary cross-cutting research field, and attracted a large number of material design experts in the world.
Functional polymer materials - conductive polymer materials
Liquid crystal polymer as a new class of high-performance materials, has greatly attracted the attention of the scientific community and industry, has been widely used, and developed into one of the most active areas of polymer science.
Liquid crystal polymers
Bamboo flooring
Carpet can be made of durable wool or PET carpet
Mainly water-based coatings, powder coatings and radiation-curing coatings
Used for outdoor landscaping products: recyclable plastics are used to make benches, tables, and traffic signs.
Green building materials
Biodegradable polymer materials
Currently, the pollution of nature exists in the "white" (plastic) and "black" (rubber) garbage. The development of biodegradable products is necessary and urgent, but many specific problems can not be solved.
1, biodegradable plastic bags low load-bearing capacity; 2, biodegradable plastic bags dull yellow color, low transparency; 3, is the price is high, the cost is difficult to accept.
Disposable medical supplies such as infusion tubes, medicine bottles, medical adhesives. Diagnostic equipment such as hearing rash, endoscopes and a variety of other diagnostic equipment.
Extracorporeal devices such as artificial limbs, hemodialysis or perfusion devices.
Human organs such as cardiac catheters, cardiac patches, artificial heart pump materials, tracheal tubes, artificial bladders, artificial meninges, arterial patches, artificial blood vessels and artificial joints.
Plastic surgery materials such as facial plastic implants.
Biodegradable materials are those that can be decomposed by body fluids, enzymes or microorganisms, and are used for sutures, implants, controlled-release medications, and so on.
Types of medical polymer materials
Artificial heart
Biomaterials
Artificial joints
Artificial kidneys
Composites with special characteristics
Carbon fiber composites
Glass fiber reinforced plastic composites
To date, the Nobel Prize winners of Polymer Science
H. Staudinger (1977-1986), a member of the Chinese Academy of Sciences, has been awarded the Nobel Prize for Polymer Science. H. Staudinger (Germany) : Introduced the concept of "polymer" into science and established the relationship between viscosity and molecular weight of polymer solutions (Nobel Prize 1953)
K. Ziegler (Germany), G. Natta (Italy) : Coordination polymerization of ethylene and propylene (Nobel Prize 1963)
P . J. Flory (USA): Principles of polymerization reactions, relationship between physical properties and structure of polymers (1974 Nobel Prize).
H. Shirakawa (Japan), Alan G. MacDiarmid (USA), Alan J. Heeger (USA): Discovery and development of electrically conductive polymers (Nobel Prize 2000).
de Gennes (France) :Soft matter, universality, scaling, magic ladder.
2. Scientific development of polymers in China
l China's polymer research began in the early 1950s, Tang Aoqing in 1951, published the first scientific paper on polymers.
l Changchun Institute of Applied Chemistry started to synthesize rubber in 1950 (Wang Fosong, Shen Zhiluan);
l Feng Xinde started to major in polymer chemistry in Peking University in 1950s.
l He Binglin carried out research on ion exchange resins at Nankai University in the mid-1950s.
l Qian Renyuan established the Polymer Physics Research Group in 1952 at the Institute of Applied Chemistry, and carried out research on polymer solution properties.
l Qian Baogong started the research on the viscoelasticity and radiation chemistry of polymers in the early 50's at the Institute of Chemical Engineering.
l Mr. Xu Xi started the plastic engineering program at Chengdu Institute of Technology (Sichuan University) in early 1950s.
l Mr. Wang Baoren established the research group of PMMA and PA6 in Shanghai Organic Research Institute in 1952.
China and the field of polymer academicians of the Chinese Academy of Sciences: Wang Baoren Feng Xinde He Binglin Qian Baogong Qian Renyuan Yu Tongyin Xu Xi Wang Fosong Cheng Rongshi Huang Baotong Zhuo Renxi Shen Jiacong Lin Shang'an Shen Zhi Tsuen Bai Chunli Zhou Qifeng Cao Yung Yang Yuliang and so on.
The twenty-first century of polymer science
In the history of mankind, there is almost no science and technology such as polymer science has made such a great contribution to human society. At the dawn of the twenty-first century, polymer science and its related technologies are facing new opportunities and challenges.
Some of the areas of opportunity and challenge:
1. Catalytic processes and new polymerization methods
2. Polymers with nonlinear structures
3. Supramolecular assemblies and highly self-organized macromolecules
4. Polymer crystallization and morphological engineering
5. Stimulus-responsive polymers
6. Recycling and Processing
Direction of Development of Polymer Materials
1.High Performance
2.High Functionality
3.Composite
4.Refinement
5.Intelligence
We should pay attention to the study, cross-discipline, independent thinking, and independent innovation, in order to contribute to the development of the national economy, to solve the problems existing in the production practice, to solve the problems in the academic field, and to improve the quality of the products. We should focus on learning, cross-discipline, independent thinking, independent innovation, for the development of national economy, solve the production practice of academic problems, improve the academic level of polymer science.
From the above description of the development of materials can be seen, the development of science is endless, a moment of satisfaction and resting on the status quo will lead to backwardness, and constantly enterprising, continuous innovation in order to make a difference.
Human needs is the driving force behind the development of science
Polymer physics teaching content to reveal the structure of polymer materials and properties of the intrinsic connection between the basic laws.
Polymer structure is the basis of polymer performance, performance is a reflection of polymer structure, polymer molecular motion is the bridge between structure and performance. That is, through the understanding of molecular motion to establish the structure and performance of the intrinsic link, master the structure and performance of the relationship between the synthesis, modification, processing to improve the performance of polymers to meet the needs of the polymer molecular design and materials design to lay a scientific foundation for the synthesis of polymer materials, processing, molding, testing and application of the theoretical basis.
Second, the teaching content of polymer physics
Chain structure of polymers
Condensed structure of polymers
Polymer solutions
Molecular weight and molecular weight distribution
Transformation and relaxation of polymers
Rubber elasticity
Viscoelastic polymers
Polymer yielding and fracture. Yield and fracture of polymers
Rheological properties of polymers
Other properties of polymers
Two, the teaching content of polymer physics
Structure of polymers: including the structure of polymer chains and condensed structure, chain segments, flexibility, spherical crystals, lamellar crystals, molecular weight and molecular weight distribution, theta solution concept.
Properties of polymer materials: mechanical properties, thermal, electrical, optical, magnetic properties. Mechanical properties include tensile properties, impact properties, silver grain, shear band, strength, modulus.
Molecular motion of polymer: glass transition, viscoelasticity, entropy elasticity, crystallization kinetics, crystallization thermodynamics, melting point, rheological properties, viscosity, non-Newtonian fluid.
WLF equation,Avrami equation,rubber equation of state,Boltzmann superposition principle.
Highlights of Polymer Physics
Relation between Polymer Structure and Properties
HOW Research Methods
Structure: Long Chain, Flexibility, Entanglement, Segmental Motion
Properties: Lightweight, Easy to Color, Toughness, Resistant to Corrosion,
Easy to Work with, Damping, Biocompatibility, Easy to Cut
WHY Research Purpose of research
Guide the design of macromolecules
Guide the processing
Development of macromolecular materials
1. Characteristics of the structure of polymers (compared with small molecules)
1) Chain structure of macromolecules: macromolecules are made up of a very large number of structural units (103-105 quantitative orders).
② polymer chain flexibility: polymer chain of internal rotation, resulting in a very large number of conformations (such as: DP = 100 PE, the number of conformations 1094), can make the main chain bent and flexible.
3) The polymer structure has polydispersity and inhomogeneity.
④The complexity of polymer condensed structure: crystalline, amorphous, spherical crystal, tandem crystal, single crystal, straight chain crystal and so on. The structure of the aggregation state of the physical properties of polymer materials has a very important impact.
Polymer materials (plastics, rubber, fibers,) has the following advantages:
① light weight, relative density is small. LDPE (0.91), PTFE (2.2)
② good electrical properties and insulating properties.
③Excellent thermal insulation performance, insulation materials.
④Good chemical stability, chemical solvent resistance.
5 good abrasion resistance, fatigue resistance. Rubber is an irreplaceable material for tires.
6 good self-lubrication, used for bearings, gears.
7 Good light transmission. Resin-based discs, resin lenses.
8 wide range of mechanical selectivity.
9 raw materials from a wide range of sources, easy processing and molding, suitable for mass production, low cost.
⑩ beautiful decorative. Can be arbitrarily colored, surface modification.
2. Performance characteristics of polymer materials
Nature and use
Plastic
Fiber
Rubber
Coating
Adhesive
Functional polymers
Polymer as the basis for the addition of (or not) a variety of auxiliaries and fillers, the formation of the plastic or rigid materials through processing. Rigid materials.
Highly elastic materials with reversible deformation.
Fine and flexible filaments, at least 100 times longer than their diameter.
Polymeric materials that can be applied to the surface of an object to form a tough film for decorative and protective purposes
Polymeric materials that can be bonded together by adhesive means
Fine polymeric materials that have special functions and uses but are not used in large quantities
3. Applications of Polymers
Polymer plastics in agriculture: (1) films, (2) irrigation tubes, (3) irrigation pipes, (4) irrigation pipes, (5) irrigation pipes, (6) irrigation tubes, (7) irrigation tubes, (8) irrigation tubes, (9) irrigation tubes and (10) irrigation tubes. Film ② Irrigation pipes
Construction industry: ①PVC, HDPE for water supply and drainage pipes ②Plastic doors and windows ③Paints and coatings
④Laminates for flooring, furniture, artificial timber, flooring ⑤PVC ceiling
Packaging industry: ①Plastic films: PE, PP, PS, PET, PA, etc.
2 Hollow containers: PET, PE, PP, etc.
3 Polymer materials applications
4 Polymer materials are also used in the construction industry.
3. Foam: PE, PU, etc.
Automotive industry: plastic parts, instrument panels, safeties, fuel tanks, cushions, etc.
Military industry: solid fuel for aircraft and rockets (oligomers), composite fibers, etc.
3. Polymer applications
Polymer materials are used in a wide range of industries and in various fields: packaging, agriculture, forestry, fisheries, construction and agriculture. Agriculture, forestry, animal husbandry and fishery, construction, electronics, transportation, household, machinery, chemical industry, textile, medical and health care, toys, education, office, furniture and so on.
Electrical industry: ① insulating materials (thermal conductivity, resistivity), etc., conductive polymer
② electronics: communications fiber optics, cables, wires, CD-ROMs, cell phones, telephones
③ household appliances: shell, liner (TV, computer, air conditioning), etc.
Medical and health care applications: artificial heart, artificial organs, artificial kidneys (PU),
Artificial muscles, infusion tubes, blood bags, syringes,Dissolvable sutures, drug release, etc.
Anti-corrosion engineering: corrosion resistance, anti-corrosion structural materials. Such as water pipe valves (PTFE):
230 ~ 260 ℃ long-term work, suitable for high-temperature corrosion of serious products.
Functional polymers: ion exchange resins, polymer separation membranes, high water absorption resins,
photoresist, photoresist, medical polymers, liquid crystal polymers,
highly conductive polymers, electroluminescent polymers and so on.
3. Application of polymer materials
4. Knowledge of polymer physics to solve practical production problems
①Molecular weight, molecular weight distribution affects the performance of polymer materials:
Large molecular weight: the material is strong, but the fluidity of the material deteriorates in the processing, the molecular weight should be moderate.
Molecular weight distribution:
a fiber, distribution of narrower, high molecular weight components of the strength of the performance is not good.
bRubber: average molecular weight is large, difficult to process, so after plasticizing, lower molecular weight, so that the distribution of broader plasticizing effect.
②condensed structure affects the performance of polymer materials:
crystallization makes the material strength ↑, brittle, toughness ↓.
In addition, the size of the ball crystal also affects the performance, the ball crystal can not be too large.
Can add nucleating agent, reduce the size of the ball crystal; change the crystallization temperature, more nucleation.
③ Processing technology affects the performance of polymer materials:
Low viscosity, easy to process. Polycarbonate, change the temperature, reduce viscosity. And polyethylene: change the screw speed, increase the injection pressure and shear → reduce viscosity.
5. How to learn polymer physics
Polymer physics content, concepts, clues, relationships, mathematical derivation. Closely grasp the relationship between structure and properties of polymers as the main line, the molecular motion and thermal transition as a bridge between the structure and properties of the relationship between the fragmented knowledge into one.
Listen carefully in the classroom, pay attention to the concepts and methods, and summarize the rules.
We should pay attention to the development of self-learning ability, in the classroom and outside the classroom can read carefully. The first is to think independently, and to work out the examples and exercises by hand.
The teaching method of heuristic is the leading one, abolishing the old injection teaching method.
[1] He Manjun, Chen Weixiao, Dong Ximan, Polymer Physics, Shanghai, Fudan University Press, 1990.
[2]Ma Dezhu, He Pingsheng et al, Structure and Properties of Polymers, Beijing, Science Press, 1995.
[3]B. Wunderlich, Macromolecular Physics, Academic Press, New York, 1973.
[4]P. J. Flory, Principles of Polymer Chemistry, Cornell Uni. Press, New York, 1953.
[5]de Genes P. G., Scaling Concepts in Polymer Physics, Cornell Uni. Press, New York, 1979.
[6]G. R. Strobl, The Physics of Polymer, Springer, 1979. The Physics of Polymer, Springer, 1996.
Good luck!